Method of obtaining oxids of nitrogen.



W. A. PHILLIPS.

METHOD OF OBTAINING OXIDS 0F NITROGEN.

APPLIOATION FILED JULY 10, 1911.

Patented Aug. 13, 1912.

,Ziz 061a Z02 PHILLIPS), of London, England, (whose post- To all whom arm -001mm UNITED STATES PATENT OFFICE.

WILLIAM .anmm rmmm LONDON, ENGLAND, ASSIGNOR T NITROGEN a l Lnvrrrnncr LONDON, ENGLAND.

,METHOD or OBTAINING oxxns or'nrrnoenu.

" Be it knowndha't l,- \NILLIAM ALFRED .Hill, in" the county of London, England,)

electricalengine'er, have inventeda certain new'and seful Method of Obtaining Oxids otNitroge11-.' ofqwhioh the following is a specification. v v

It; wafs discoi'erd by Priestley 1111788 I that when hydrogen and "air are exploded together in a glass vessel the water pro- ;duced is acid, "and that the acid was nitrous acidwas proved by Vithcring. In Gmelins Hamilbool: of Chemistry published in 1849 it is mentioned thatwater produced by the schen Cheqm'sbhe Gesellschoft, 39 i (1906) 940, 2557), and it is now generally admitted that atmospheric nitrogen can be oxidized by-the combustion of gases in air.'

"The chief attempts which have been made to apply flames of burning gases to the commercial production of oxids of ni- -trogen have consisted in burning combustibles.' nitrogcn and oxygen in a furnace whose mouth is immersed in water; in

burning carbon monoxid under pressure and. in the, torniof a Steady flame in the presence of oxygen and nitrogen while avoiding tl'zcprcsence of hydrogen; and in causing air to pass up a chamber containing a munl cr of .jets of hydrogen or hydro-carbon flame. the directionot' travel of air being parallel to -the flame, the object being to produce as complete an int'ermixture of the air with the burning gases as may be possible.-

My experimentshave led me to the conclusion that the formation of oxidized nitrogen occurs on the surface of the flame and that theproblem of the con'nnercial aplication of the phenomenon is to be solved y sweeping the surface of the flame by a rapid-current of air. For a commercial yield it is essential that the surface area of I Specification of Letters Patent. Application filed ul 10,1911. Serial No. 637,726.

Patented a n 13,1912.

the flame should he as large as possible per unit volume of gas consumed. and that products of incon'iplete combustion should be preventcd as tar as possible from passing forward with the air.

With these objects in View my invention consists in spreading the substantially completely oxidized flame or portion of the tiamc over a surtace and-causing air or a mixture of nitrogen and oxygen to travcl over'this spread out tiamc at a speed higher than that of the hot. gases constituting the flame.

In my early experiments l caused the {tame to impinge on a mass of pieces of refractory material and drew a current of air through the mass so as to sweep away the oxidized nitrogen. A certain success attends this method but it was found ditlicult to prevent products of imperfect combustion passing forward with the current; oi" gases. i

It preferable to cause that part of the flame which is generally regarded as substantially completely oxidized, namely in the usual hydrocarbon flame that portion which is beyond what is commonly calledthe inner cone, to play upon a single surface so that it is spread out thereon and to cause the current of air to pass over this spread out flame along a path which is removed from the immediate neighborhood of the main stream of burning gas. The temper- .ature of this, surface should be lower than that of the flame, in fact I have found that the best results were obtalned when the suriacc was cooled, 'l he tcmpcrz'iture at winch the surface should be kept is however to a certain'cxtcnt determined by the speed of flow of the air over the surface of the flame.

I find that for the llaine the heat of an ordinary Bunsen burner is quite sutlicient, though a blow pipe may be used.

.-\pparatu. for carrying out theprocess may be constructed in many different manners.

'lwo constructions are shown in vertical section in the accompanying drawings by way of example.

In Figure 1, a is a hollow truncated cone in the base of which is a number of perfora tions arranged on the circumference of a circle. The flame of a gas blow pipe b is directed into the top of the cone and so adusted that the end of the flame extends through the perforations in the bqe of the cones'o as to form a number of very short flames protruding from the cone. Thebase of thecone is placed opposite the flange c of a tube d, at a very short distance; therefrom,

say at about 5mm. Suction being applied to the endof pipe (1, air is drawn between the flange c and the base of the cone a and spreads the small flames over the under surface of the base. The suction must be such that the air travels faster than the hot gases constituting the small flames, but not so fast that the flames-are extinguished. a

. Fig. 2 represents-a number of parallel bars of iron c placed at a distance of about 3 mm. apart over a box 1 in which a diminished pressure is maintained. Over each bar is a row of Bunsenburners placed at such a distance from the bar that thedraft of air between the bars draws the parts of the flame in which combustion is substantially complete over the edges of the bars. Thesuctlon in box I must be such as to produce between the bars a 'current of air which is more rapid than the speed of travel of the hot gases of combustion moving over the surfaces of the bars. It will be noted that the. width of the bars is such that the air current travels in a path well removed from the main/gas flame. a

It is obvious that any suitablemixture of gen which proce'ss'con sists 1n causing a substantially completely oxidized flame .of combustible fluid to spread over a surface and causing a mixture of oxygen and nitrogen totravel over the spread out flame at a speed higher than that of the hot gases CQIlStliillt+ ing the flame.

2. A process of producing oxids of nitrogen which process consists in causing a substantially completely oxidized portion of a flame oi combustible fluid'to spreadover a surface and causing a-mixture of oxygen and nitrogen to travel over the spread out portion 91' flame at a speed higher than that of the hot gases constituting the flame and along a path removed from the portion of the flame which is not spread out. I

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

Witnesses:

JOSEPH MILLARD, W. J. Nonwoon;

WVILLIAM ALFRED PHILLIPS. 

